TBP萃淋树脂分离—罗丹明B分光光度法测定痕量铊

SEPARATION BY TBP-CONTAINING RESIN AND SPECTROPHOTOMETRIC DETERMINATION OF TRACE THALLIUM WITH RHODAMINE B

本文提出了在聚乙烯醇存在下,利用罗丹明B与TlBr_4-形成三元配合物,直接在水溶液中测定铊的分光光度法。在588nm处测定的摩尔吸光系数为4.2×10~4,在25ml显色液中铊含量在62.5μg以下遵守比耳定律,介绍了用TBP萃淋树脂使铊与一些共存离子分离的方法。

A spectrophotometric method for the determination of thallium in aqueous solution with rhodamine B using polyvinyl alcohol as stabilizing agent is proposed. The ion-associate co-ordinate compound, [RB] [TIBr_4], has a maximum absorption at 588nm, with the nolar absorptivity of 4.2×10~4 l·mol^(-1)·cm^(-1), Beer's law is obeyed for 0—62.5 μg Tl in 25ml. The conditions for the separation of thallium with TBP-containing resin column have been studied. Interfering ions can be removed by elating with 1.5M HCl solution. Thallium retained in column is eluted with hot 1％ NaHSO_8 solution.